(1) Field of the Invention
The present invention relates to a thermoplastic resin composition having excellent chemical resistance, moldability, impact resistance, heat resistance, coating properties, mechanical properties and appearance of molded articles made therefrom, and a method for preparing the same. This composition of the present case can be widely utilized as materials for electrical and electronic parts, machine parts, automobile parts and the like.
(2) Description of the Prior Art
The so-called engineering plastics such as aromatic polyester resins, polycarbonate resins, polyamide resins and polyphenylene ether resins have excellent mechanical properties, heat resistance, stiffness and impact resistance. Furthermore, ABS resins and polypropylenes are widely used for various molded articles because of having excellent chemical resistance, moldability and the like, and because of being inexpensive.
In recent years, with regard to not only the engineering plastics but also the ABS resins and polypropylenes, new additional functions are demanded, and various attempts have been made to achieve the same. One of them is a composition comprising a combination of plastics, and this composition has features of the respective plastics and is known as a polymer alloy.
For example, combinations of engineering plastics such as an aromatic polyester resin/a polyphenylene ether resin and a polycarbonate resin/an ABS resin have been known for a relatively long time, but examples of polymer alloys of polypropylenes and the engineering plastics are extremely limited. If a material can be provided with mechanical properties, heat resistance, stiffness, impact resistance and coating properties and the like, maintaining moldability and chemical resistance as well as inexpensiveness which are characteristics of the polypropylene, such a material will be industrially useful.
However, the polypropylene and each of such plastics as mentioned above are difficult to mix, and therefore merely by melting and mixing these materials, the polymer alloy cannot be obtained. In Japanese Patent Unexamined Publication Nos. 61-62542 and 61-64741, examples are disclosed in which polyamide resins are blended with a polypropylene, and in Japanese Patent Unexamined Publication Nos. 61-60744 and 61-60746, examples are disclosed in which aromatic polyester resins are blended with a polypropylene. In these examples, acid anhydride-modified polypropylenes and epoxy group-containing ethylene copolymers are used to facilitate the mixing of these resins. In this case, the compatibility of the two resins with each other is higher than when they are simply mixed, but there are drawbacks such as the increase in melting viscosity.
In addition, with regard to resins other than the polyamide resins and aromatic polyesters, examples of improved compatibility have not been present.